We face a crisis. If we are to rebalance our energy needs with what we can produce cleanly through renewable sources, we need a revolution in terms of the way we build.  and along with that we need to renew our transport infrastructure. Before the Industrial Revolution, buildings evolved over centuries.  Vernacular traditions were established to suit place and climate, using local materials and techniques. But traditions eroded during the steam age were finally discarded in the age of oil. Plug in an air conditioner and a building in Dubai can be identical to one in London, despite climates of opposite extremes.  The realisation that we need to relearn lessons embedded in those vernacular responses was our starting point for the design of Masdar [being built in abu Dhabi as the world's first sustainable city].  We looked at traditional settlements in the region. We found that the streets were narrow and oriented to maximise shade, and that the buildings and public spaces incorporated fountains, greenery and wind towers to encourage cooling air currents.  By applying those principles we developed buildings that require significantly less energy. Of course, you need power for lighting and the amenities of contemporary life. But by examining energy usage holistically - and generating renewable energy within the city itself - we have established a comfortable, self-sustaining environment and reduced overall consumption drastically. The result is a blueprint for a high-density, carbonneutral, zero-waste community.  Now consider that in industrialised societies buildings, and the movement of people betw